Spatiotemporal changes of pelagic food webs investigated by environmental DNA metabarcoding and connectivity analysis

Abstract

Environmental DNA metabarcoding (eDNA metaB) is fundamental for monitoring marine biodiversity and its spread in coastal ecosystems. We applied eDNA metaB to seawater samples to investigate the spatiotemporal variability of plankton and small pelagic fish, comparing sites with different environmental conditions across a coast-to-offshore gradient at river mouths along the Campania coast (Italy) over 2 years (2020–2021). We found a marked seasonality in the planktonic community at the regional scale, likely owing to the hydrodynamic connection among sampling sites, which was derived from numerical simulations. Nonetheless, spatial variability among plankton communities was detected during summer. Overall, slight changes in plankton and fish composition resulted in the potential reorganization of the pelagic food web at the local scale. This work supports the utility of eDNA metaB in combination with hydrodynamic modelling to study marine biodiversity in the water column of coastal systems. This article is part of the theme issue ‘Connected interactions: enriching food web research by spatial and social interactions’.

Connected interactions: enriching food web research by spatial and social interactions

“…This study sets the stage for understanding how these metabolic interactions influence broader ecological processes and community dynamics. In the second study on this theme, Bellardini et al [49] (P2) broaden the scope by investigating the spatiotemporal changes in pelagic food webs using environmental DNA metabarcoding. This technique allows for the identification of community composition across different times and locations.…”

“…The interactions and productivity of these microscopic organisms influence biological organization at all hierarchical levels, from individual cells to populations, communities and broader ecosystems. This theme issue includes studies [48][49][50] which explore the intricate dynamics of phytoplankton within marine ecosystems using advanced DNA-based techniques, global databases and innovative statistical methods.…”

“…In the second study on this theme, Bellardini et al . [ 49 ] (P2) broaden the scope by investigating the spatiotemporal changes in pelagic food webs using environmental DNA metabarcoding. This technique allows for the identification of community composition across different times and locations.…”